• Research in Plant Disease
• /
• v.26 no.4
• /
• pp.256-263
• /
• 2020

Incidence of Fusarium wilt was surveyed in fields of summer radish in Gangwon province in Korea in 2018 and 2019. The disease started in early July and spread rapidly in hot summer of late July and August and in severe case, reached up to 80% in a field in Gangneung area. Symptoms in the seedling stage include poor growth and browning of internal tissue of root. During mid-growth, the leaves of diseased plant turned yellow over time, the surface of the roots changed from white to blackish, and the vascular tissues turned brown. A total of 23 isolates was obtained from the diseased plants and identified as Fusarium oxysporum f. sp. raphani by elongation factor-1α and intergenic spacer sequence analysis. Pathogenicity of the isolates was tested by artificial inoculation to the radish and other plants. All the isolates tested were pathogenic to radish plant, although there were differences in virulence on radish 11 cultivars. However, the isolates were not virulent to other plants except some cruciferous vegetables including Brussels sprouts, rocket, stock, and turnip. The results of pathogenicity test showed that it is necessary to rotate with crops other than cruciferous vegetables in order to prevent Fusarium wilt from radish fields.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.22 no.2
• /
• pp.121-127
• /
• 1977

Leaf burning due to nitrofenapplication was characterized as brown color spot appearing on the leaf sheath and blade. The spots predominantly appeared around 5-7 cm high above soil surface regardless of different particle size, formulation, application method, or water level. Magnitude and frequency of burn spots increased somewhat as the granular size gets finer, by higher water level, or in transplanted rice compared to directly sown rice when applied at 7 leaf-stage, but there was no indication of increase in leaf burning due to clinging of floating dust to rice plant. When collections from local distributor's stock of TOK 7G, a granular formulation of nitrofen, were analyzed for particle size composition, 98.9% by weight ranged between 9 to 35 meshes, and only about 0.08% by weight was of particles finer than 100 mesh.

• Journal of Animal Science and Technology
• /
• v.54 no.4
• /
• pp.267-274
• /
• 2012

The method of sexing based on differences in the rate of feather growth provides a convenient and inexpensive approach. The locus of feather development gene (K) is located on the Z chromosome and can be utilized to produce phenotypes that distinguish between the sexes of chicks at hatching. To establish the auto-sexing native chicken strains, this study analyzed the genotype frequency of the feathering in domestic chicken breeds. The method of classification of slow- and rapid-feathering chickens was also investigated. In the slow-feathering chicks, the coverts were either the same length or longer than the primary wing feathers at hatching. However, the rapid-feathering chicks had the primary wing feathers that were longer than the coverts. The growth pattern of tail feather also distinctively differed between the rapid- and slow-feathering chicks after 5-days. The accuracy of wing feather sexing was about 98% compared with tail sexing. In domestic chicken breeds, Korean Black Cornish, Korean Rhode Island Red, and Korean Native Chicken-Red had both dominant (K) and recessive ($k^+$) feathering genes. The other breeds of chickens, Korean Brown Cornish, Ogol, White Leghorn, Korean Native Chicken-Yellow, -Gray, -White and -Black had only the recessive feathering gene ($k^+$). Consequently, feather sexing is available using the domestic chicken breeds. Establishing the maternal stock with dominant gene (K-) and paternal stock with recessive gene ($k^+k^+$), the slow-feathering characteristic is passed from mothers to their sons, and the rapid-feathering characteristic is inherited by daughters from their fathers.

• Korean Journal of Poultry Science
• /
• v.39 no.4
• /
• pp.283-290
• /
• 2012

The objective of this study was to compare the growth performance between Korean native layer chickens and imported layer chickens at early rearing stage. Total number of chicks analyzed in this study was 276 and feeding period was conducted from July 24, 2012 for 10 weeks. Five strains including 2 Korean native strains: A=Korean Native Black (Chungcheongbuk-do) and B=Korean Native Yellowish Brown (Gyeongsangbuk-do) and 3 imported layer strains: C=White Leghorn (Gyeongsangnam-do), D=White Leghorn (Seoul), and E=Ameraucanas (Gyeongsangbuk-do) were used to analyze the following traits such as fertility, hatchability, body weight at a different growing stage, average body weight gain, and feed conversion ratio. The fertilities and hatchabilities of strains were 93.88% and 95.65% in strain A, 81.75% and 86.24% in strain B, 82.25% and 88.15% in strain C, 79.25% and 90.85% in strain D, and 71.50% and 88.11% in strain E, respectively. A viability was excellent in strains A and E to be more than 98% and was low in strain D to be 86.67% at a whole week. The strain A had greater body weight during growing stages (p<0.05) than the other strains. The shank length of strain D of $56.69{\pm}3.27mm$ was the highest value at 10 weeks of age among strains (p<0.05). The phenotypic correlation coefficients of strains A and D between an average body weight gain and a shank length were 0.63 and 0.73 during 0~2 wk, 0.70 and 0.55 during 2~4 wk, 0.55 and 0.54 during 4~6 wk, 0.50 and 0.24 during 6~8 wk, and 0.46 and 0.29 during 8~10 wk, respectively. The Korean native hens may have potential abilities to be used as an excellent seed stock for poultry industry.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.37 no.4
• /
• pp.254-263
• /
• 2017

This study was carried out to introduce of agronomic characteristics, forage yields and quality of Sorghum ${\times}$ Sudangrass hybrids 'Cadan 99B' and 'Sweet Sioux WMR' from 2015 to 2016 in middle and southern regions of Korea. The field experiment design was complete in seven varieties with three repetitions. Sorghum ${\times}$ Sudangrass hybrids were sown on mid-May in middle region, and end-May in southern region of Korea, in 2015 and 2016. The observed average heading date of Cadan 99B and Sweet Sioux WMR were July 22. The heading dates of Cadan 99B and Sweet Sioux WMR were 8 days earlier than SX-17 and 5 days earlier than brown mid-rid (BMR) Revolution. The sugar contents of Cadan 99B and Sweet Sioux WMR were 6.5 and $6.9Brix^{\circ}$, respectively. Comparison with BMR variety, the sugar contents of Candan 99B and Sweet Sioux WMR were 0.2 and $0.6Brix^{\circ}$ higher than Revolution, respectively. The average of dry matter (DM) yield for 2 years and 2 regions of Cadan 99B (24,587kg/ha) were the highest among the seven varieties, but there was no significant difference among other varieties except headless control variety Jumbo (19,119kg/ha) and LATTE (20,778kg/ha) (p>0.05). The crude protein (CP) and in vitro dry matter digestibility (IVDMD) of Cadan 99B were 7.5% and 60.2%, and Sweet Sioux WMR were 6.9% and 60.7%, respectively. The results of this study indicated that Sorghum ${\times}$ Sudangrass hybrids Cadan 99B and Sweet Sioux WMR are earlier heading dates and higher than SX-17, and high yields of DM in middle and southern regions of Korea.

• Korean Journal of Plant Resources
• /
• v.16 no.3
• /
• pp.264-274
• /
• 2003

Many potato genetic resources have been collected and improved for their diverse traits over the years using breeding program in KPGR. To select potential varieties for table and processing in Korea, 58 elite potato breeding lines and several 'Valley' varieties were cultivated and harvested at Korea Alpine area in 2001. The cultivated lines and varieties were evaluated using their cultural adaptability in the environment and tuber characteristics, such as the depth of tuber eye, tuber shape, skin color, flesh color, scab resistance, yield, and the resistance of hollow heart and internal brown spot disease. Additionally, in the selection of potential processing varieties, reducing sugar content (sum of glucose and fructose concentration) of tubers is critically considered, because it mainly influence on the chip color of processing potato tuber. For table stock varieties with white skin color, 'Early Valley', 'Summer Valley', 'Winter Valley', and 'Taebok Valley' were selected. In the aspect of diverse potato tuber color, several varieties were selected such as 'Golden Valley' for its yellow fresh and skin color, 'Gogu Valley', 'Juice Valley', and 'Rose Valley' for their red skin color, and 'Purple Valley' for its purple skin. Compared with world wide known processing cultivar 'Atlantic', 24 lines (or varieties) were selected for the potential potato processing industry due to their low reducing sugar contents (below 0.3％), high yield (above 4.0 ton/ha), and unique chip colors. Selected white chipping varieties were 'Taedong Valley', 'Kangshim Valley', and 'Kangwon Valley', which have 0.23％, 0.27％, and 0.29％ of reducing sugar contents, respectively. 'Bora Valley', having deep purple color in both skin and fresh, was selected for purple chip variety and has 0.26％ of reducing sugar content. Light yellow chip varieties (lines) were 'Rose Valley' and Valley 54, having 0.19％ and 0.269％ of reducing sugar content, respectively. For French frying potatoes, 'Stick Valley' of 0.22％ and Valley 72 of 0.151％ in reducing sugars were selected. All of these selected lines and 'Valley' varieties can be used as parents to improve potato genetic resources and to develop better varieties with unique traits and colors.

• Korean Journal of Poultry Science
• /
• v.48 no.3
• /
• pp.101-110
• /
• 2021

In this study, we performed a cross-combination test using offspring from two paternal and five maternal parent stock lines to produce a new synthetic breed of Korean native commercial chickens. The survival rate, body weight, feed intake, and feed efficiency were measured for 10 crosses, with 837 Hanhyup-3 chickens used as a control. Most chickens had brown-based feathers, and there was little difference in color phenotypes among combinations. The average survival rate of the combinations was 94.9%, which was significantly different from that of Hanhyup-3 at 75.3% (P<0.01). There was significant differences in body weight among the combinations at all weeks of age (P<0.01). At 10 weeks of age, the FHHY combination was the heaviest with 2,300 g, while the weight of Hanhyup-3 was 1,922 g. In addition, the weight difference between the male and female chickens was 458 g. As a result of regression analysis, the duration needed to reach 1.9 kg was about 61 days for the FHFY, FHHY, and HFFY combinations, and 70 days for Hanhyup-3, exhibiting a 9-day difference. The average feed conversion ratio of the combinations until 10 weeks was 2.42, which was significantly different from that of Hanhyup-3 at 2.97 (P<0.01). In conclusion, FHHY, FHFY, and HFFY were determined to be the best new breed combinations based on production capacity. When these combinations are used as new commercial breeds, they are expected to increase the average weight by 18% and improve feed efficiency by 19%, as compared to the existing Hanhyup-3 breed.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.20 no.1
• /
• pp.41-51
• /
• 1987

This study was carried out to prepare powdered smoked-dried mackerel which can be used as a soup base, and to examine storage stability and the taste compounds of Products. Raw mackerel are filleted, toiled for 10 minutes and pressed to remove lipids, and then soaked in extract solution of skipjack meat. This soaked mackerel are smoked 3 times to $10-12\%$ moisture content at $80^{\circ}C$ for 8 hours. And the smoked-dried mackerel were pulverized to 50 mesh. Finally, the powdered smoked-dried mackerel were packed in a laminated film $bag(PET/Al\;foil/CPP:\;5{\mu}m/15{\mu}m/70{\mu}m,\;15\times17cm)$ with air(product C), nitrogen(product N) and oxygen absorber(product O), and then stored at room temperature for 100 days. The moisture and crude lipid content of powdered smoked-dried mackerel was $11.3-12.3\%,\;12\%$, respectively, and water activity is 0.52-0.56. And these values showed little changes during storage. The pH, VBN and amino nitrogen content increased slowly during storage. Hydrophilic and lipophilic brown pigment formation showed a tendency of increase in product(C) and showed little change in product(N) and (O). The TBA value, peroxide value and carbonyl value of product(N) and (O) were lower than those of product (C). The major fatty acids of products were 16:0, 18:1, 22:6, 18:0 and 20:5, and polyenoic acids decreased, while saturated and monoenoic acids increased during processing and storage of products. The IMP content in products were 420.2-454.2 mg/100 g and decreased slightly with storage period. And major non-volatile organic acids in products were lactic acid, succinic acid and $\alpha-ketoglutaric$ acid. In free amino acids and related compounds, major ones are histidine, alanine, hydroxyproline, lysine, glutamic acid and anserine, which occupied $80.8\%$ of total free amino acids. The taste compounds of powdered smoked-dried mackerel were free amino acids and related compounds (1,279.4 mg/100 g), non-volatile organic acids(948.1 mg/100 g), nucleotides and their related compounds (672.8 mg/100 g), total creatinine(430.4 ntg/100 g), tetaine(86.6 mg/100 g) and small amount of TMAO. The extraction condition of powdered smoked-dried mackerel in preparing soup stock is appropriate at $100^{\circ}C$ for 1 minute. Judging from the results of taste and sensory evaluation, it is concluded that the powdered smoked-dried mackerel can be used as natural flavoring substance in preparing soups and broth.